1. Field of the Invention
The present invention relates to an electrophotographic photoconductive member and an image forming apparatus. More particularly, the present invention relates to an electrophotographic photoconductive member which is excellent in electrical characteristics and also can suppress generation of cracks in a photoconductive layer and black spots arising from the cracks in the formed image, and an image forming apparatus equipped with the electrophotographic photoconductive member.
2. Description of the Related Art
As an electrophotographic photoconductive member, which has hitherto been used in an image forming apparatus, a photoconductive member having an organic photoconductive (OPC) layer containing a charge generating material, a charge transferring material (a hole transferring material or an electron transferring material) and a binder resin is used. Such a photoconductive member having the OPC layer has an advantage that it is easily produced as compared with a conventional electrophotographic photoconductive member having an inorganic photoconductive layer and also has a high degree of freedom of design because of a wide selection range of photoconductive materials.
It is required for the charge transferring material to have a high charge transfer rate so as to impart high electrical characteristics to the electrophotographic photoconductive member.
Japanese Unexamined Patent Publication (Kokai) No. 2005-289877(Patent Document 1) discloses, as a hole transferring material having a high charge transfer rate, an amine compound represented by the following general formula (33):
wherein, in the general formula (33), Ar1 represents a benzene ring having one or more substituents, a condensed aromatic ring which may have a substituent, a heterocycle which may have a substituent, or a condensed heterocycle which may have a substituent; Ar2 represents a benzene ring which may have a substituent, a condensed aromatic ring which may have a substituent, a heterocycle which may have a substituent, or a condensed heterocycle which may have a substituent; and n represents an integer of 1 to 3.
The amine compound represented by the general formula (33) has a high charge transfer rate. However, a photoconductive layer containing such an amine compound has a problem that it easily separates from a substrate and cracks are easily generated. There is a problem that, when an oil component such as sebum of a human hand or grease of a driving roller adheres onto the surface of an electrophotographic photoconductive member, cracks are easily generated around the point on which the oil component is adhered in the photoconductive layer. Also there is a problem that such cracks cause generation of black spots in the formed image.